Thursday, January 21, 2010

Should You Take Vitamin D2 Or Vitamin D3?

Michael Holick's opinion: It doesn't matter.

Michael Holick's opinion matters.

Dr. Holick discovered the mechanism for how vitamin D is made in the skin. He identified the major circulating form of vitamin D3 in human blood (calcidiol also known as 25-hydroxyvitamin D3 or 25(OH)D3. This is the form that's measured to determine deficiency states.)

He was the first person to isolate and identify the active form of vitamin D (1,25-dihydroxyvitamin D3).

He's the author of The UV Advantage and the soon-to-be-released The Vitamin D Solution.

Vitamin D2, also known as ergocalciferol, is derived from plants (notably yeast).Vitamin D3, also known as cholecalciferol, is derived from animals (notably sheep's wool).

In his study...

Vitamin D2 Is As Effective As Vitamin D3 In Maintaining Circulating Concentrations Of 25-Hydroxyvitamin D, Journal of Clinical Endocrinology & Metabolism, March 2008

Dr. Holick and his colleagues gave participants one of the following daily for 11 weeks at the end of the winter in Boston:

Placebo

1000 IU vitamin D2

1000 IU vitamin D3

Combination of 500 IU vitamin D2 and 500 IU vitamin D3

And found:

"The rise in the total 25(OH)D was identical to that observed for the groups who received either 1000 IU vitamin D2 or 1000 IU vitamin D3."

"That, to me, proves that vitamin D2 is as effective as vitamin D3 in raising and maintaining 25-hydroxyvitamin D levels. That is consistent with the early literature that showed that 100 IU of vitamin D2 was effective in preventing rickets in children."1

6 comments:

At the end of the trial none of the participants had a 25(OH)D level above 30ng/ml they all remained vitamin D insufficient. IMO it is unacceptable medical practice to knowingly give people an amount of a supplement that leaves them at such a low 25(OH)D level they remain unable to properly absorb calcium and well below the 58.8ng/ml level at which human breast milk flows replete with D3.So too little vitamin D of any kind leaves you vitamin D deficient.Is that such a remarkable finding?

Grassrootshealth Banner Graph shows the amounts people have been taking and the 25(OH)D levels they have achieved. 6000~8000iu approx 1000iu/daily for each 25lbs you weigh generally produces a natural level at which the body is able to store a sufficient reserve of D3 to be effective at times of crisis. This LEF study is another example showing 5000iu/d is not sufficient to get most people above 50ng/ml.

As Holick knows perfectly well human skin naturally makes 10,000iu/daily given a few minutes full body UVB exposure. It does that for a purpose. Only when researchers start using equivalent EFFECTIVE amounts of the same NATURAL Vitamin D3 biologically identical to the form human skin NATURALLY makes, will we see an improvement rates of chronic illness.

The case against Ergocalciferol as a vitamin supplement shows D3 is more effective lasts longer and is safer. Holick's research did not raise levels to that at which human DNA works as it evolved to function. The level his people attained was just half the amount required to enable breast milk to flow replete with D3.At natural levels, human bodies normally achieve living naked outdoors, 60~80ng/ml we know D2 makes the bode catabolize vitamin D at a faster rate. This means the more D2 you take the more your body tries to get rid of it. Just look at the FIG. 2. here and you see the guys taking D2 were below the starting point after 15 days whereas those on D3 were still fine at the end of the month. D2 is fine for rats and for plants but not for humans. Sure getting Vitamin D3 from sun is fine BUT you cannot rely on UVB reaching the ground if you live under a flight path or in or near a town. Atmostpheric pollution absorbs/blocks UVB. Look what happens in practiceNow who had the greatest amount of UV exposure?Who had the highest 25(OH)D levels. Again those women only achieved, at best, levels half that required for optimum function. In practice no one is going to get regular full body sun exposure if they live/work in normal society. We have to accept that supplements are the best way of attaining and maintaining optimum 25(OH)D levels between 60~80ng/ml. 150~200nmol/l.

As we know that 10,000iu/daily is safe even in sunny countries the question of liver damage is simply hypothetical. It takes 40,000iu/daily for months and months to maybe raise 25(OH)D to levels that may cause harm. There is no evidence that at the amounts needed for most people (1000iu/for each 25lbs weight)any harm occurs. The evidence shows people with higher levels live longer, experience less infection, suffer less pain, have fewer heart attacks and less cancer incidence. I could go on listing the benefits that those with higher D3 levels enjoy. You cannot support the claims you have made anonymous.

TedHutchinson, You say the question of oral doses of vitamin D and liver damage is hypothetical, is a hypothesis. I agree. The link between oral intake of vitamin D - or between blood levels of vitamin D, as 25(OH)D - and longer life, and pain, and cancer, and heart attacks are hypothetical as well.